Coffee and tea are part of daily life for billions of people, but how they affect bone health as we age has been surprisingly hard to pin down. Now, a new study from Flinders University offers clearer insight into how these habits may relate to bone mineral density in older women.
Researchers followed nearly 10,000 women age 65 and older for 10 years, tracking both their beverage intake and bone mineral density at the hip and femoral neck. These areas are especially important because weakening in either raises fracture risk, a major concern given that one in three women over 50 will experience osteoporosis.
The study, published in Nutrients, found that women who drank tea had slightly higher total hip bone density compared with non-tea drinkers. The increase was modest but consistent.
“Even small improvements in bone density can translate into fewer fractures across large groups,” said Adjunct Associate Professor Enwu Liu from the College of Medicine and Public Health.
Coffee showed a more mixed pattern. Moderate intake, roughly two to three cups per day, did not appear harmful. But drinking more than five cups daily was linked to lower bone density. Women with higher lifetime alcohol consumption also saw more negative effects from coffee, while tea appeared particularly beneficial for women with obesity.
The researchers point to possible biological explanations. Tea contains catechins that may support bone formation and slow bone breakdown.
“Coffee’s caffeine content, by contrast, has been shown in laboratory studies to interfere with calcium absorption and bone metabolism, though these effects are small and can be offset by adding milk,” said co-author Ryan Liu.
Still, the differences seen in the study were not large enough to warrant dramatic changes for individuals. As Associate Professor Liu explained, “Our results don’t mean you need to give up coffee or start drinking tea by the gallon.” Instead, the findings suggest that moderate tea drinking could play a small supportive role in bone health and that very high coffee intake may not be ideal for some women.
“While calcium and vitamin D remain cornerstones of bone health, what’s in your cup could play a role too,” he said.
The results also highlight how everyday nutrition habits interact with broader aging processes. For many older women, a daily cup of tea might be more than a comforting ritual. As Liu noted, it could be a small step toward stronger bones.
This study used data from the Study of Osteoporotic Fractures, funded by the National Institute on Aging and the National Institute of Arthritis and Musculoskeletal and Skin Diseases.